Regulating device for telephone relays and transmitters.



110. 836,612. E PATENTED Nov 20, 1906. H. E. SHREEVE. RBGULATING DEVICE FOR TELEPHONE RELAYS AND TRANSMITTBRS.

APPLICATION FILED OOT. 26.1905.

2 SHEETS-SHEET 7- IN VEN TOR.

EMMA-(8 Br 1.4m

ATTORNEY.

PATENTED NOY ZO, 1906.

1 H. E. s EEEvE. REGULATING DEVICE EOE TELEPHONE RELAYS 'AND TRANSMITTBRS.

APPLIOATIOHIILED OOT. 26. 1906.

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WITNESSES: v INVENTOR.

I 1 arlfq wfi- W W 1 I (o I ATTORNEY.

NITED STATES PATENT OFFICE.

AMERICAN TELEPHONE AND TION OF NEW YORK.

TELEGRAPH COMPANY, A CORPORA- REGULATING DEVICE FOR TELEPHONE RELAYS AND TRANSMITTERS.

Specification of Letters Patent.

Patented Nov. 20, 1906.

Application filed October 26, 1905- Serial No. 234,450.

To all whom it may concern.-

Be it known that I, HERBERT E. SHREEVE,

' residing at Newton, 1n the county of Middle- This is efiected by including a winding of sex and State of Massachusetts, have invented certain Improvements in Regulating Devices for Telephone Relays and Transmitters, of which the following is a specification.

This invention relates to lmprovements in telephonic instruments or apparatus-such as current'reinforcers, relays, and transmittors-which embody as an element thereof a granular carbon button or microphone; but the invention is especially intended as an improvement upon the telephone-current reinforcers or relays of my Patents Nos. 791,655 and 791,656, dated June 6, 1905.

The present invention is designed as a remedy for the packing of the carbon gran ules in the carbon chamber or button employed in such reinforcers or relays and telephones; and itconsists in the combination, with one of the walls of the said carbonchamber, which is preferably one .of the electrodes, either the back electrode or the ordinary front electrode, of an impedance coil, a condenser, and an electromagnet, the said condenser being in the local circuit of said carbon-chamber, while the said imedance-coil and said electromagnet are in a parallel branch or shunt of the same local circuit around said condenser, and said electromagnet being arranged to impart movement to said movable wall of said carbonchamber.

The invention also consists, particularly in its application to current reinforcers or relays, in utilizing the electromagnet which sets up the strong initial magnetic field, the latter to be varied by the feeble rapidly-varying voice-currents which are to be relayed, to perform in conjunction with other parts the additional function of overcoming packing of the granular carbon in its chamber.

said magnet in a local circuit through the granular carbon. This local circuit may, if desired, be the local reinforcing and transmitting'circuit through the granular carbon, in which case the path of current from one pole of the generator to the microphone is preferably divided into two parallel branches, one including a condenser and the other an impedance-coil and said magnet-winding.

ing properties 0 struments of in part to the natural tendency of the carbon.

hon-chamber.

In relays such as described in my patents above enumerated and to a lesser extent in the granular carbon transmitter used independently of relays there is a tendency of the granules in the carbon-chamber to pack, such packing imfpairing the resistancevarythe mass in responding to relative vibrations of the electrodes, and consequently diminishing the transmitting efliciency ofthe ap aratus. Such packing of the carbon granu esa defect inherent in inthis type-is, it is believed, due

granules to settle toward the bottom of the chamber, particularly under the influence of the slight relative vibrations of the electrodes in the normal operation of the instrument, in part to the constant and slight vibrations gomg on everywhere, and particularly in buildings where such apparatus are likely to be located, in part to the expansion efiects of heat generated in the button, including the granular carbon thereof, by the passage of current therethrough in the normal operation of the apparatus, and possibly to other causes which need not be mentioned.

This invention consists, further, in certain details of construction.

The applicability of the invention to telephone-current reinforeers. or relays will be sufiiciently illustrated by diagrams which may, if desired, be=read in connection with my patents above enumerated.

Figure 1 is a diagram representin the invention as applied toa relay in w 'ch the combination of the condenser, impedance coil, and electromagnet is, with the ordinary movable wall or front electrode of the car- Fig. 2 is a diagram representing a similar combination as acting upon the rear or opposite wall of the carbon-chamber. .Fig. 3 represents the invention as employed with a granular-carbon tele hone.

The invention as illustrated in ig. 1 will formed by a heavy solid back B, on which is first be described. A is the carbon-chamber, screwed a ring R, so as to hold between them a vibrating front electrode E, to which is rigidly secured a pole-piece P, partakin of its vibrations, or rather Whose end-to-en vibrations the electrode follows. D is the back electrode secured to a metallic piece D of equal diameter. A projection D from D ro hereinafter.

passes through a hole in back B, anut I) holding the metallic piece D and the back electrode D in position, suitable insulation of hard rubber b and If being provided, as

shown. G is the granulated carbon within the carbon-chamber. F is a spool for the winding L, forming the receiving' par tofthe I 5 C is-a condenser. The independefit winding H and impedance-coil I are in one branch of the local circuit, forming a closed path for steady currents, while the condenser C is in another parallel branch open to steady curzo rents, but closed for rapidly-varying currents.

That portion of said ocal circuit outside of these two branches includes the relay-battery B, the'primary of an induction-coil, (Whose secondaries are connected with the line to be relayed,) the front and back elec trodes Eand D, the granulated carbon G of the carbon-chamber, and the ring R. This local circuit maybe traced as follows: First, the path for rapidly-varying currents from one pole of the battery B by Wire 1 to one end of the primary 2O ofthe induction-coil N, from the other end of the primary 20 by wire 2 to the projection D back electrode D, granular carbon G, front electrode 5 E, ring R, wire 3, terminal or division post 7,

condenser 0, wire 8, back to the other pole of battery B". The path for steady currents through the impedance-coil and winding H is the same as just describedfrom one pole of the battery B to terminal or division post 7,-

thence by Wire 9 to one end of winding H, from the other end of winding'H by wire 10 to impedance-coil I,by wire 11 to terminal or division post 4, and by wire 8 back to the other 4 5 pole of battery B. An important office of the ,winding H is the same as that of the similar second winding upon the similar spool in my said Patent No. 791,655viz., to establish a strong initial magneticfield to be varied by feeble pulsations or alternations coming over the linewires, as hereinafter further explained. Another office of the windin H relates to the present invention. W en from any cause the ranules in the carbonchamber become pac ed, and hence their resistance to passage of current diminished, the direct current in the local circuit through the impedance-coil and winding shunting the condenser is thereby abnormally increased,

and this increase causing winding H to act upon the variable pole P to impart an extraordinary movement to the electrode E draws said electrode away from the carbon in the chamber, loosening the mass of particlesand the contact thereof with one or both elecase,e12

trodes. This results in a sudden material increase of the resistance of the button and like diminution in the current flowing through the Windlng'H. The pulling power of the relay drops, releasing the electrode E, which having been placed under tension fonoibl and vigorously moves inward to its norma position and contracts the chamber, (for the instant to less than itsnormal size,) the impact of the inwardly-moving wall against the carbon mass breaking it down and spreading its component particles loosely throughout the chamber. This extraordinary movement ofthe electrode "E first in one direction and then in the other, which, asexplained, occurs only when the carbon granules have become detnimentally packed in their chamber, being'much stronger than the ordinary movements or soundvibrations effects a material displacement, disintegration, loosening, and consequent unpacking of the granules, thereby restoring them to their normal unpacked or loose condition. Any subsequent repacking reproduces the conditions which will again automatically unpack the granules in the manner ex lained. This is'believed to be thecorrect exp anation of the manner in which the expansion and contracticn of the chamber effects the loosening of the packed carbon mass, although ithas been found impossible to actually observe the changes which take place therein in operation, owing to the inclosing of said mass, the almost imperceptible movements which effect the changes, and the swiftly successive and recurrent character of the changes. The feeble rapidly-varying voice-currents coming over the line 30 3O circulate in the receiving or magnetization-varying coil L,

.thereby varying the initial magnetization and the attraction of the magnet, and hence vibrating the movable pole-piece P 'corresponding to such attraction variationsand to the electrical variations or voice-currents of the circuit-traversing coil L. Thisv vibration of the pole-piece (which may be referred to as the ordinary movement thereof to distinguish from the extraordinary movement heretofore mention'edas overcoming packing of the carbon granules) actuates electrode E which in turn acts upon the carbon particles to vary the resistance therethrough of the local circuit ofbattery B, thereby producing in said local circuit strong pulsating currents corresponding to the feeble Lvoice curre ts coming in over line'3O 30. Through the ac? tion of primary winding, ZOand'ifsecOndary windings 45 the local circuit reproducesthe strong pulsating currents in the outgoing line 40 40. The strong pulsating'voice currents produced in the local circuit, as above explained, are forced by the impedance-coil to take the path through the condenser, thereby preventing a cycle of reactions, which would cause-the phenomenon of singing if the ing to impart my said previous patents I have found it sufficient employing a carbon button of the ordinary size to give the condenser C a value of four microfarads and to use an impedancecoil consisting of five thousand three hundred and twenty turns of No. 23 copper wire wound aroundan iron core. In the electromechanisms of my said former patents, upon which the present invention is an improvement, an important feature is the control of the polepiece rigidly secured to the front electrode of the transmitting portion of the relay by a coil in the receiving portion of the relay in the manner hereinbefore explained. The connections of this coil (marked L in the figure under consideration) with the line which is to be relayed may briefly be stated as follows: 30 30 are the two wires of the incoming line, and 40 40 are the two wires of the outgoing line, or 40 40 may be regarded as the incoming and 30 30 as the outgoing line. They connect, as shown, with the ends of two secondary windings 45 45 of the induction-coil N, the primary of which has been mentioned, which have at their middle points the terminals 35 35 ofa bridge composed of wires 50 50, connected with the two ends of the winding L, designed to set up end-to-end vibrations of the variable pole P. The windings of the secondaries 45 45 upon each side of the terminals 35 35 are in the same direction, so that currents in the secondaries shall be in the same direction, reinforcing one another in the main circuit.

Instead of employing, as in Fig. 1, an .electromagnet energized by a Winding 1n the local circuit through the granular carbon to establish the strong initial magnetic field and utilizingthe same magnet and its said windto one electrode of the microphone the extraordinary movement which unpacks the carbon in the embodiment of the invention illustrated in Fig. 2 I have shown a ermanent magnet for establishing the initial magnetic field and an independent electromagnet in the localcircuit through the carbon for the impartation of such desired extraordinary movement of the electrode. In this fi ure of the drawings is illustrated the com ination of impedance-coil, condenser, and electromagnet with the back electrode of the carbonchamber A which saidchamber is formed in this instance by screwing a thimble T into a front piece T so as to hold between them the front electrode E and then screwing upon the thimble T a back piece T so astohold bet-ween them a mica plate M D is the preferably of carbon, secured to a metallic piece D of equal diameter, a (projecton T from which passes hrough sai back electrode mica plate M through a back T and through an iron plate T", which is screwed upon said pro eetion and serves as an armature for an electro- Inagnet I-l ,\\'hose oilice will appear. (i is the granulated carbon. P is the vibrating polepiece rigidly connected with front electrode E and entering about half-way a spool F upon whiehis wound the winding 1 whose ends are connected by bridge-wires 50 50 with induc tion-coil N. M is a permanent magnet, a fixed but adjustable pole-piece 1'' being screwed tlierethrough, as shown. This magnet and fixed pole-piece establish the strong magnetic field to be vaired by feeble alternations coming over the main line. The inductioncoil N is the same as the induction-coil used in Fig. 1, and its connections with the delicate receiving apparatus of the relay shown at Fig. 2 are the same as in Fig. l. I is an impedance-coil. G is a condenser, and B is the relay-battery. The local circuit may be traced as follows: from one pole of battery B by wire w to one end of the primarylt) of induction-coil N, from the other end of primary 20 by wire w to terminal 25, thence by Wire w" and condenser wire to to terminal t, by wire w to back electrode D granulated carbon G front electrode E wire to, to the other pole of battery 13, or from terminal t by wire 'w to impedance-coil P, to wire 11: to electromagnet H terminal F, &c.

It will be readily seen that when from any cause the granules in the carbon-cliamber shown at Fig. '2 pack the direct current in the local circuit through the winding of the electromagnet II will draw back the back electrode D from the carbon-chamber. effecting an unpacking of the carbon in substantial y the manner explained with refer-- ence to Fig. 1,with consequent increase of resistance and decrease of current in the local circuit. The resiliency of the mica plate M affords suilicient movement or play to the back electrode I) for the purposesof the invention. It will be observed in Fig. 2 that no bridge or similar support is used to hold the back electrode of the button. The bridge is not essential, provided the electrode has a sufficient amount of inertia. It is unnecessarv to further describe the operation of the apparatus shown in Fig. 2-.

The application of the invention to an ordinary carbon-button transmitter (fully illustrated in Fi 3) requires but a brief descrip-' tion, since -t e construction very closely resembles that of the telephone-current relay shown in Fig. 2. The carbon button G is thus put together: A thimble T is screwed into a bridge-piece R and on said thimble outside of the bridge-piece are screwed front piece F and a back piece B, holding between said thimble and said pieces mica plates it 6 and M forming movable walls for the carbon-chamber, to which are secured the front and back electrodes E and E, the former of which is rigidly secured to the diaphragm D of the transmitter. G7 is the granular carbon. H is an electromagnet bolted, as

shown, to a second bridge-piece R, which is secured to the first bridge-piece R by screws. (Not shown.) T is an iron plate forming an armature for electromagnet H. Outside of said transmitter B is the local battery, C is the condenser, and I is the impedance-coil. N is an induction-coil for connecting the transmitter and the additional parts involving the present invention with the line w over which the voice-currents are to be transmitted, B being an ordinary telephonereceiver. t, t, and t are insulated terminals or division-posts. The circuits may be traced as follows: from one pole of the battery B by Wire w to one end of the primary p of the induction-coil N from the other end of primary 22 by wire to to terminal t thence (for rapidly-varying currents) by wire to and condenser wire 10 to division-post 11 by wire w to back electrode E granulated carbon G front electrode E", Wire w to insulated post i, wire w to other pole of battery B or for steady currents from terminal t by Wire w to impedance-coil I ,Wire w", insulated'post t", wire 10 to electromagnet H to division-post t &c.

What I claim is- 1. In a'telephone or telephone-current relay employing finely-divided variable-resistance material as an essential part of the transmitting portion, the combination with the said variable-resistance material, a battery or source of electromotive force in circuit therewith, and a movable electrode in the chamber containing said resistance material, of an electromagnet adapted to control said movable electrode, an impedance-coil, and a condenser, the said electromagnet and impedance-coil, and the said condenser, shunting one another, or being respectively in parallel branches of the circuit of said source of electromotive force and variable-resistance material.

2. In a telephone-cunent relay or analogous instrument employing a chamber containing granulated carbon in a local circuit as the transmittin portion of said relay, one wall of said cham ber being made movable, the combination with said movable wall and the battery or source of electromotive force in said local circuit, of an electromagnet adapted to control said movable wall of said chamber, an impedance-coil and a condenser,

coil shunting said condenser in said ocal circuit.

3. In a telephone-current relay or analogous instrument employing an electromagnet as an essential part of the receiving portion of the relay and a granulated carbon button as the transmitting portion, the winding of said electromagnet being adapted to operatethe front electrode of said button by currents in said winding coming over the main line, the combination with said button and said electromagnet, of a local circuit including a battery, an impedance-coil, a condenser, and a second Windingfor said electromagnet, the said impedance-coil and said second winding shunting said condenser in said local circuit.

4. Ina telephone-current relay or analogous instrument employing an electromagnet and having a granulated carbon button as its transmitting portion, said electromagnet having two windings and being adapted to operate one electrode of said button b currents coming over a main telephone-line to one of said windings, the combination with leading through the granular carbon of saidbutton and including a generator and the other winding of said magnet.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 23d day of October, 1905.

HERBERT E. SHREEVE.

Witnesses:

GEO. WILLIs PIERCE, JosEPH A. GATELY.

the said electromagnet and said impedance- 1 said button and magnet of a local circuit 

